This invention relates generally to support systems, and more particularly to a system for supporting what is referred to in the trade as "cable tray", which is a support structure comprising a pair of parallel rails connected by cross members and used in commercial buildings to support long runs of electrical wiring, conduit and the like.
Prior to the present invention, cable tray has been supported in different ways, such as by a series of parallel support bars suspended (as by vertical rods) at intervals spaced lengthwise of the cable tray. The cable tray rests on these support bars and is held in position on the bars by hold-down members which are affixed to the support bars by suitable fasteners (e.g., bolts). These hold-down members are intended to prevent lateral shifting of the cable tray in the event the support bars tilt for some reason. However, if the hold-down members on a support bar are not tightened securely, there is a risk that they will slip under the load of the cable tray, allowing the cable tray to shift sideways and possibly even fall off of the support bar. To reduce the risk of this happening, the fasteners affixing the hold-down members to the support bar must be tightened very securely, which is burdensome to the person doing the tightening and which requires the use of heavy-duty fasteners capable of withstanding the forces involved.